1. Field of the Invention
The present invention relates to a recording apparatus for recording information on a recording medium, and, more particularly, to a recording apparatus that records and erases a visible image on and from a recording medium which can thermally record and erase a visible image repeatedly.
2. Description of the Related Art
Conventionally, to obtain hard copy, an image is formed on a recording medium like paper with a developer material, such as ink or toner, which is externally supplied, or a visible image is formed on a recording layer, provided on the base material like paper, to provide a permanent image as on a thermal recording paper.
Due to the recent construction of various types of electronic networks and popularity of facsimiles and copying machines, the amount of consumption of those recording media has rapidly and excessively increased. This phenomenon has raised various social problems, such as destruction of natural environment like the destruction of forests or woods, and waste disposal. To cope with those problems, there is a strong demand for the reduction of the amount of consumption of recording media including the recycling of recording sheets. As one way to meet this demand, recording media which can repeatedly record and erase images have been receiving attention.
As a recording medium having such a characteristic, there has been proposed a recording medium which changes its state from a transparent state to a opaque state as the temperature of the recording medium rises from T1 to T2, and stays opaque even when the temperature returns to T1. When the temperature rises above T2 till T4 from T1, and then returns to T1 again, this recording medium returns to the transparent state from the opaque state and stays transparent thereafter. This transition can occur repeatedly.
With the transition from transparent state (initial) to opaque state (recording), then to transparent state (erasure) being treated as one cycle, the opaque characteristic and transparent characteristic of recording media which exhibit reversible transition between opaque and transparent states through a heat treatment will change as the number of cycles increases. This change is more prominent in the opaque characteristic. As the number of cycles increases, the recording medium tends to become opaque with lower energy. If image is recorded with the same recording energy as the initial level, the recording density would be lowered considerably or the service life through repetitive use would be shortened with the excessive power.
Recording apparatuses usually perform recording/erasing operations under almost the same given conditions regardless of the number of cycles. In the recording/erasing systems in the conventional recording apparatuses, therefore, recording/erasing can be executed on a recording medium without problems after several usages, but the recording density would become considerably low or the service life through repetitive use would be shortened when the recording medium is used scores to several hundreds times.